Retention of carbon fiber post system within the root canal and core retention

This study was directed to evaluate the retention of two core build up materials, composite resin and silver amalgam, and retention of carbon fiber post system within the root canal in comparison to Parapost system after treatment with universal dental adhesive. Specimens of each group were subjected to tensile load to test the retention. The results revealed a significant difference in the retention between the two post system studied. Also carbon fiber post system showed high retention values when used with universal dental adhesive to the root canal or composite resin core material

Marginal adaptation of porcelain versus direct composite laminate veneers

This in vitro study investigated the effect of three different designs of teeth preparations on the seal of porcelain and composite resin laminate veneers to tooth structure. Two main groups of 30 teeth were prepared for labial veneers. The first main group was restored with porcelain laminate veneer while the teeth of the other main group were, restored with light cured microfilled composite resin laminate veneer. The veneers were stored in a distilled water for I week. Afterwards, longitudinal sectioning of the teeth was done and the extent of microleakage was measured at four interfaces :[1] cervical tooth/composite; [2] cervical porcelain composite; [3] incisal enamel/composite and [4] incisal porcelain/composite. The results revealed that the cervical and incisal edge [feathered] interface has a significantly higher leakage value [P<0.05] than the other three interfaces when using other technique of preparation